Yes, it's true the Cubs haven't won a ring since 1908.
On the other hand, individual (ex)Cubs have won a ring. As this future Cubs championship season progresses, we're going to highlight Ex-Cubs who have won rings with other teams. Because the Cubs are playing the Reds this week, we're highlighting the ex-Cubs who won rings with Cincinnati.
(Note: In order to qualify for recognition, they must have already been ex-Cubs when they won the ring.)
He was the backup catcher during the Cubs dynasty (1906-1910), but he was also a great manager--leading the Cincinnati Reds to a World Series title in 1919. Hmmm. Let's see...who did they beat that year? Oh that's right, the White Sox.*
He was the ace of the Cincinnati staff during the 1919 season, but he started his career with the Cubs. The Cubs obviously misjudged ol' Dutch (they released him after only a half-season in 1917), because he went on to win Game 1 of the 1919 World Series for the Cincinnati Reds against the White Sox.*
In 1937 Lonnie Frey backed up three all-stars in the Cubs infield; second baseman Billy Herman, shortstop Billy Jurges, and third baseman Stan Hack. The Cubs sold him to the Reds before the 1938 season, and by 1940 he was the starting second baseman on the World Series champs. He led the team in walks, stolen bases and triples, but he didn't do so well in the series; going 0-20 in three World Series appearances. When his career was pretty much over, he rejoined the Cubs (1947).
He was a hard throwing youngster on the Cubs in the mid-60s, pitching for a manager who hated youngsters--Leo Durocher. That doomed his stay in Chicago, but it certainly didn't hurt him in Cincinnati where he was one of the starting pitchers for the Big Red Machine in '75 and '76. He started game 4 of the 1975 World Series and game 2 of the 1976 World Series, and the Reds won the series both times (although Norman didn't get a win in either game).
He debuted in the major leagues as a Cub in 1984, and got some real playing time for the team in 1985 when the Cubs suffered through a lot of outfield injuries (especially to Gary Matthews and Bobby Denier), but the Cubs traded him for Jerry Mumphrey before the 1986 season. Hatcher turned out to be a gem--a stolen base threat with pop in his bat. In the 1990 World Series for the Reds (managed by Lou Piniella), Hatcher hit an unbelievable .750, and was named the Babe Ruth award winner as the MVP of the series.